The present invention relates to a method for controlling task process and a device thereof and, more particularly, to a method for controlling task process and a device thereof used in, for example, a public telephone set which performs speech processing for telephone communication and other processing, such as coin discrimination.
In recent public telephone sets processing, such as speech processing for sending a dial signal and coin discrimination processing are performed by using a stored program type processor, i.e., a microprocessor.
There are different types of processing or operations to be performed in these public telephone sets. One is an irregular request, such as coin discrimination accompanied by coin detection upon insertion of a coin, and the other is a regular, long-term request, such as rate calculation accompanied by reception of a rate signal.
In order to place the conventional public telephone in the different request modes, there are two types of processing control systems: (a) one system wherein an irregular request, such as coin discrimination, requires quick response, so that a special circuit or computer is used to respond only to an irregular request, and (b) the other system wherein a clock frequency or processing cycle is determined on the basis of the response speed for the irregular request, so that both irregular and regular requests can be responded to and predetermined operations can be performed by a single computer.
However, according to system (a), at least two computers must be used and the circuit arrangement becomes complicated. On the other hand, system (b) is operated such that the rate calculation program runs even without the rate calculation request, so that the computer is always operating, resulting in time loss and high power consumption. As a result, system (b) is not suitable for an office power supply type public telephone set since the power consumption thereof is limited.